SpringBoot 集成 Redis

1. 集成 Redis

1.1 导入依赖包

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

补充：
进入 spring-boot-starter-data-redis.pom 文件查看，默认使用的是lettuce

<dependency>
  <groupId>org.springframework.data</groupId>
  <artifactId>spring-data-redis</artifactId>
</dependency>
<dependency>
  <groupId>io.lettuce</groupId>
  <artifactId>lettuce-core</artifactId>
</dependency>

若要使用 jedis，需要排除lettuce

<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>4.2.3</version>
</dependency>

1.2 配置文件

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://mysql.sqlpub.com:3306/spotlive
    username: xxx
    password: xxx
  redis:
    database: 0
    host: 127.0.0.1
    port: 6379
    password: admin
    jedis:
      pool:
        max-active: 8
        max-idle: 8
        min-idle: 6

1.3 示例

@RestController
@RequestMapping("/redis")
public class RedisController {

    private final RedisTemplate redisTemplate;

    public RedisController(RedisTemplate redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    @GetMapping("/set")
    public String save(String key, String value){
        redisTemplate.opsForValue().set(key, value);
        return "success";
    }

    @RequestMapping("/get")
    public String getValue(String key) {
        return redisTemplate.opsForValue().get(key).toString();
    }

    @RequestMapping("/all")
    public String getAll() {
        // return JSON.toJSONString(redisTemplate.keys("*"));
        return JSON.toJSONString(redisTemplate.keys("*o*"));
    }
}

2. 序列化问题

查看key值，出现无意义的乱码前缀

127.0.0.1:6379> keys *
1) "\xac\xed\x00\x05t\x00\x04name"

原因是 Redis 默认使用的是JdkSerializationRedisSerializer

public class RedisTemplate<K, V> extends RedisAccessor implements RedisOperations<K, V>, BeanClassLoaderAware {
    public void afterPropertiesSet() {
        super.afterPropertiesSet();
        boolean defaultUsed = false;
        if (this.defaultSerializer == null) {
            this.defaultSerializer = new JdkSerializationRedisSerializer(this.classLoader != null ? this.classLoader : this.getClass().getClassLoader());
        }
        // ...
    }
}

方式一：使用 StringRedisTemplate

@Resource
private StringRedisTemplate stringRedisTemplate;

方式二：设置RedisTemplate序列化

@Configuration
public class RedisConfig {

    @Bean(name = "redisTemplate")
    public RedisTemplate<String, Object> getRedisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(factory);

        StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
        redisTemplate.setKeySerializer(stringRedisSerializer);
        redisTemplate.setValueSerializer(stringRedisSerializer);

        redisTemplate.afterPropertiesSet();
        return redisTemplate;
    }
}

使用：

@Resource
private RedisTemplate redisTemplate;

2.2 其他

@Configuration
public class RedisConfig {

    @Bean(name = "redisTemplate")
    public RedisTemplate<String, Object> getRedisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(factory);

        StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
        redisTemplate.setKeySerializer(stringRedisSerializer);
        redisTemplate.setValueSerializer(jacksonSerializer());
        redisTemplate.setHashKeySerializer(stringRedisSerializer);
        redisTemplate.setHashValueSerializer(jacksonSerializer());

        redisTemplate.afterPropertiesSet();
        return redisTemplate;
    }

    private Jackson2JsonRedisSerializer jacksonSerializer() {
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        objectMapper.activateDefaultTyping(LaissezFaireSubTypeValidator.instance,
                ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);
        jackson2JsonRedisSerializer.setObjectMapper(objectMapper);
        return jackson2JsonRedisSerializer;
    }
}